During pipe drawing or other piping work, one or more bends may be made, and a pipe also may be branched off to one or more branch pipes. Pipes having diameters from 7-8 mm and above are difficult to bend, and the bends, therefore, must be performed in a different way. Usually, triangular cuts or cutouts are made in the pipe to be bent, whereafter the pipe is bent, and the cutout surfaces contacting each other are welded together. It also is possible, instead of making in the pipe triangular cutouts or cuts, to joint such cuts to a bend. In both these cases, however, it is very complicated and tedious to calculate a suitable number of cuts for every bend as well as to calculate and determine the size and form of each cut. Normally, the respective cuts are spread out on a paper, and for each cut a template is made. The cutting then is carried out manually with aid of the templates.
During conventional welding-on of branch pipes or so-called extension pipes to a conduit, it is also often necessary to first prepare a template both for the hole in the conduit and for the end of the branch pipe, and thereafter by help of these templates to cut out the hole and to form the end of the branch pipe, so that the end fits the hole cut-out in the conduit. This work, too, is very tedious and complicated and, besides, requires high skill, particularly if the branch pipe is to be welded on a conduit at an angle of less than 90.degree. therebetween.